Smallest possible force

I have a lab for physics that I have to demonstrate the smallest possible force. The force has to be mearsured by multiplying the mass of the designated object by acceleration. It has to have a continuous and positive acceleration. The distance is that it must travel at least 30 cm. Any ideas and help would be great :).

I had an idea using the air track with a paper clip but it would be kinda typical for our class since everyone is doing it since no one knows what to do.

Unless I missed something (which is quite possible because I'm on my 8th beer), you didn't mention what the mass is of the body in question. And even when you do divulge it, you're going to have to work it out yourself. I don't know what you mean by 'demonstrate'. That could indicate either a mathematical proof of your conclusions, or a physical staging.

well... as for displaying how it works, wouldn't the objet moving be evidence of the force?

as for figuring out force, u need it to be traveling 1cm/min idealy on average
make a graph of distance over time, that being 30cm over 30 mins, take the dirivative(sp?) to get speed(remember u have to start with a speed of 0), then the dirivative(sp?) of that to get acceleration, then figure out the force from that...